Refactor and extract DefaultPaginationStrategy.

This commit is contained in:
Andreas Brandl 2018-04-25 15:19:55 +02:00
parent 7e78eacd2a
commit cc1d141127
2 changed files with 65 additions and 54 deletions

View File

@ -2,67 +2,80 @@ module API
module Helpers
module Pagination
def paginate(relation)
relation = add_default_order(relation)
relation.page(params[:page]).per(params[:per_page]).tap do |data|
add_pagination_headers(data)
end
DefaultPaginationStrategy.new(self).paginate(relation)
end
private
class DefaultPaginationStrategy
attr_reader :ctx
delegate :params, :header, :request, to: :ctx
def add_pagination_headers(paginated_data)
header 'X-Per-Page', paginated_data.limit_value.to_s
header 'X-Page', paginated_data.current_page.to_s
header 'X-Next-Page', paginated_data.next_page.to_s
header 'X-Prev-Page', paginated_data.prev_page.to_s
header 'Link', pagination_links(paginated_data)
return if data_without_counts?(paginated_data)
header 'X-Total', paginated_data.total_count.to_s
header 'X-Total-Pages', total_pages(paginated_data).to_s
end
def pagination_links(paginated_data)
request_url = request.url.split('?').first
request_params = params.clone
request_params[:per_page] = paginated_data.limit_value
links = []
request_params[:page] = paginated_data.prev_page
links << %(<#{request_url}?#{request_params.to_query}>; rel="prev") if request_params[:page]
request_params[:page] = paginated_data.next_page
links << %(<#{request_url}?#{request_params.to_query}>; rel="next") if request_params[:page]
request_params[:page] = 1
links << %(<#{request_url}?#{request_params.to_query}>; rel="first")
unless data_without_counts?(paginated_data)
request_params[:page] = total_pages(paginated_data)
links << %(<#{request_url}?#{request_params.to_query}>; rel="last")
def initialize(ctx)
@ctx = ctx
end
links.join(', ')
end
def paginate(relation)
relation = add_default_order(relation)
def total_pages(paginated_data)
# Ensure there is in total at least 1 page
[paginated_data.total_pages, 1].max
end
def add_default_order(relation)
if relation.is_a?(ActiveRecord::Relation) && relation.order_values.empty?
relation = relation.order(:id)
relation.page(params[:page]).per(params[:per_page]).tap do |data|
add_pagination_headers(data)
end
end
relation
end
private
def data_without_counts?(paginated_data)
paginated_data.is_a?(Kaminari::PaginatableWithoutCount)
def add_default_order(relation)
if relation.is_a?(ActiveRecord::Relation) && relation.order_values.empty?
relation = relation.order(:id)
end
relation
end
def add_pagination_headers(paginated_data)
header 'X-Per-Page', paginated_data.limit_value.to_s
header 'X-Page', paginated_data.current_page.to_s
header 'X-Next-Page', paginated_data.next_page.to_s
header 'X-Prev-Page', paginated_data.prev_page.to_s
header 'Link', pagination_links(paginated_data)
return if data_without_counts?(paginated_data)
header 'X-Total', paginated_data.total_count.to_s
header 'X-Total-Pages', total_pages(paginated_data).to_s
end
def pagination_links(paginated_data)
request_url = request.url.split('?').first
request_params = params.clone
request_params[:per_page] = paginated_data.limit_value
links = []
request_params[:page] = paginated_data.prev_page
links << %(<#{request_url}?#{request_params.to_query}>; rel="prev") if request_params[:page]
request_params[:page] = paginated_data.next_page
links << %(<#{request_url}?#{request_params.to_query}>; rel="next") if request_params[:page]
request_params[:page] = 1
links << %(<#{request_url}?#{request_params.to_query}>; rel="first")
unless data_without_counts?(paginated_data)
request_params[:page] = total_pages(paginated_data)
links << %(<#{request_url}?#{request_params.to_query}>; rel="last")
end
links.join(', ')
end
def total_pages(paginated_data)
# Ensure there is in total at least 1 page
[paginated_data.total_pages, 1].max
end
def data_without_counts?(paginated_data)
paginated_data.is_a?(Kaminari::PaginatableWithoutCount)
end
end
end
end

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@ -17,8 +17,6 @@ module Gitlab
end
end
private
# Methods needed by `API::Helpers::Pagination`
#